[keycloak-user] Using a role to allow access to a resource

[Guus der Kinderen]

Okay, I'm trying to wrap my head around this - please correct me if I'm
wrong:

   - All of our users are required to get all of the roles that potentially
   are used by clients. Can we automate this (we've got many users, which
   varying life cycles)?
   - In the (keycloak-sided) configuration of clients (that authenticate
   users), we limit what roles can be included in the access token that's
   generated for that client
   - In the code of the clients (that act as resource servers), we verify
   that the required role is in place (assuming that authentication itself
   succeeded in the first place).


On 1 November 2016 at 10:36, Sebastien Blanc <sblanc at redhat.com> wrote:

>
>
> On Tue, Nov 1, 2016 at 10:16 AM, Guus der Kinderen <
> guus.der.kinderen at gmail.com> wrote:
>
>> ah, no - users don't have any roles assigned.
>>
>> Should users each have individually assigned all roles that can be used?
>>
> yes
>
>> Can we prevent one client from obtaining an access token with a role
>> that's not intended to be used by that role?
>>
> Wel not directly with auth, you will still be authnticated, you can just
> limit the roles that will be contained in the token (by doing it the way
> you did it initially with client scope). Maybe with authorization you can
> achieve this.
>
>>
>> On 1 November 2016 at 10:13, Sebastien Blanc <sblanc at redhat.com> wrote:
>>
>>> Your token will contain the roles of the user, not the roles of the
>>> client. Does your user have the roles assigned ?
>>>
>>> On Tue, Nov 1, 2016 at 9:41 AM, Guus der Kinderen <
>>> guus.der.kinderen at gmail.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> While trying to authenticate a user to obtain a resource, I'm running
>>>> into
>>>> an issue. It's likely caused by my misunderstanding of how things are
>>>> supposed to work, rather than some kind of bug. I'd love to be
>>>> corrected.
>>>>
>>>> Using Keycloak 1.9.2, I've created a realm with two clients. One client
>>>> is
>>>> using the Javascript adapter[1] to create a very simply UI, that lets
>>>> the
>>>> user authenticate. The resulting access token is used to make a request
>>>> to
>>>> a REST-like service, which employs the Java Servlet Filter Adapter[2].
>>>>
>>>> We're planning to have multiple resource services like this, each
>>>> exposing
>>>> data for which different levels of authorization might be required.
>>>>
>>>> I'd like our REST-like service to provide data only when the user that
>>>> requests the data has an access token that is issued to a front-end
>>>> that is
>>>> allowed to access this data. To achieve this, I tried employing the use
>>>> of
>>>> a role. I think this is where I'm messing up somehow.
>>>>
>>>> What I did:
>>>>
>>>> In the realm, I've a added a "realm role" ( "scope param required" /
>>>> "composite roles" both disabled)
>>>>
>>>> In the client configuration that's used by the Javascript UI (which
>>>> generates the access token), I've made these changes to the "scope" tab:
>>>>
>>>>    - Disabled "Full Scope Allowed"
>>>>    - Moved the role that I added earlier from "available roles" to
>>>>
>>>>    "assigned roles"
>>>>
>>>> Finally, I've modified the implementation of the REST-like service to
>>>> check
>>>> for the new role, by doing something like this simplified code in a
>>>> servlet
>>>> (that's covered by the OIDC Filter):
>>>>
>>>> KeycloakSecurityContext securityContext = (KeycloakSecurityContext)
>>>> request.getAttribute( KeycloakSecurityContext.class.getName() );
>>>> if ( !securityContext.getToken().getRealmAccess().isUserInRole(
>>>> "the-role-that-I-added" ) )
>>>> {
>>>>     response.setStatus( HttpServletResponse.SC_FORBIDDEN );
>>>>     return;
>>>> }
>>>>
>>>> This throws a NullPointerException, as getRealmAccess() returns null.
>>>>
>>>> While debugging the code, it's appears that the access token itself is
>>>> received and valid - it's the scope / role check that does not appear to
>>>> come through.
>>>>
>>>> I finally used the service at https://jwt.io/ to inspect the content
>>>> of the
>>>> access token that's being generated. I expected the
>>>> 'the-role-that-I-added"
>>>> value to be in there somewhere, but that's not the case.
>>>>
>>>> That's where I thought it'd be a good idea to get some advice, and here
>>>> we
>>>> are. I'd love some feedback.
>>>>
>>>> Regards,
>>>>
>>>>   Guus
>>>>
>>>> [1]:
>>>> https://keycloak.gitbooks.io/securing-client-applications-gu
>>>> ide/content/topics/oidc/javascript-adapter.html
>>>> [2]:
>>>> https://keycloak.gitbooks.io/securing-client-applications-gu
>>>> ide/content/topics/oidc/java/servlet-filter-adapter.html
>>>> _______________________________________________
>>>> keycloak-user mailing list
>>>> keycloak-user at lists.jboss.org
>>>> https://lists.jboss.org/mailman/listinfo/keycloak-user
>>>>
>>>
>>>
>>
>